package com.tj.jinzao.widgets;

import android.animation.Animator;
import android.animation.ValueAnimator;
import android.annotation.SuppressLint;
import android.content.Context;
import android.graphics.Matrix;
import android.graphics.RectF;
import android.graphics.drawable.Drawable;
import android.support.v7.widget.AppCompatImageView;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.ScaleGestureDetector;
import android.view.ScaleGestureDetector.OnScaleGestureListener;
import android.view.View;
import android.view.View.OnTouchListener;
import android.view.ViewTreeObserver;

import com.tj.jinzao.utils.Trace;


/**
 */
public class ZoomImageView extends AppCompatImageView implements OnScaleGestureListener,
        OnTouchListener, ViewTreeObserver.OnGlobalLayoutListener {
    private static final String TAG = ZoomImageView.class.getSimpleName();
    private static final float SCALE_MAX = 3.0f;
    private static final float SCALE_MID = 0.8f;

    /**
     * 初始化时的缩放比例，如果图片宽或高大于屏幕，此值将小于0
     */
    private float initScale = 1.0f;
    private boolean mOnce = true;

    /**
     * 用于存放矩阵的9个值
     */
    private final float[] mMatrixValues = new float[9];

    /**
     * 缩放的手势检测
     */
    private ScaleGestureDetector mScaleGestureDetector = null;
    private final Matrix mScaleMatrix = new Matrix();

    /**
     * 用于双击检测
     */
//    private GestureDetector mGestureDetector;
    private boolean mIsScaling;
    private int mTouchSlop;

    private float mLastX;
    private float mLastY;

    private boolean mCanDrag;
    private int mLastPointerCount;

    private boolean mIsCheckTopAndBottom = true;
    private boolean mIsCheckLeftAndRight = true;

    public ZoomImageView(Context context) {
        this(context, null);
    }

    public ZoomImageView(Context context, AttributeSet attrs) {
        super(context, attrs);
        super.setScaleType(ScaleType.MATRIX);
//        mGestureDetector = new GestureDetector(context,
//                new SimpleOnGestureListener() {
//                    @Override
//                    public boolean onDoubleTap(MotionEvent e) {
//                        if (mIsScaling == true)
//                            return true;
//
//                        float x = e.getX();
//                        float y = e.getY();
//                        Trace.e("DoubleTap", getScale() + " , " + initScale);
//                        if (getScale() < SCALE_MID) {
//                            ZoomImageView.this.postDelayed(
//                                    new AutoScaleRunnable(SCALE_MID, x, y), 16);
//                            mIsScaling = true;
//                        } else if (getScale() >= SCALE_MID
//                                && getScale() < SCALE_MAX) {
//                            ZoomImageView.this.postDelayed(
//                                    new AutoScaleRunnable(SCALE_MAX, x, y), 16);
//                            mIsScaling = true;
//                        } else {
//                            ZoomImageView.this.postDelayed(
//                                    new AutoScaleRunnable(initScale, x, y), 16);
//                            mIsScaling = true;
//                        }
//
//                        return true;
//                    }
//                });
        mScaleGestureDetector = new ScaleGestureDetector(context, this);
        this.setOnTouchListener(this);
        initAnimator();
    }

    //回弹系数
    private final float xx = 1.01f;

//    /**
//     * 自动缩放的任务
//     */
//    private class AutoScaleRunnable implements Runnable {
//        static final float BIGGER = 1.07f;
//        static final float SMALLER = 0.93f;
//        private float mTargetScale;
//        private float tmpScale;
//
//        /**
//         * 缩放的中心
//         */
//        private float x;
//        private float y;
//
//        /**
//         * 传入目标缩放值，根据目标值与当前值，判断应该放大还是缩小
//         *
//         * @param targetScale
//         */
//        public AutoScaleRunnable(float targetScale, float x, float y) {
//            this.mTargetScale = targetScale;
//            this.x = x;
//            this.y = y;
//            if (getScale() < mTargetScale) {
//                tmpScale = BIGGER;
//            } else {
//                tmpScale = SMALLER;
//            }
//
//        }
//
//        @Override
//        public void run() {
//            // 进行缩放
//            mScaleMatrix.postScale(tmpScale, tmpScale, x, y);
//            checkBorderAndCenterWhenScale();
//            setImageMatrix(mScaleMatrix);
//
//            final float currentScale = getScale();
//            // 如果值在合法范围内，继续缩放
//            if (((tmpScale > 1f) && (currentScale < mTargetScale))
//                    || ((tmpScale < 1f) && (mTargetScale < currentScale))) {
//                ZoomImageView.this.postDelayed(this, 16);
//            } else
//            // 设置为目标的缩放比例
//            {
//                final float deltaScale = mTargetScale / currentScale;
//                mScaleMatrix.postScale(deltaScale, deltaScale, x, y);
//                checkBorderAndCenterWhenScale();
//                setImageMatrix(mScaleMatrix);
//                mIsScaling = false;
//            }
//
//        }
//    }

    @SuppressLint("NewApi")
    @Override
    public boolean onScale(ScaleGestureDetector detector) {
        float scale = getScale();
        float scaleFactor = detector.getScaleFactor();

        if (getDrawable() == null)
            return true;

        /**
         * 缩放的范围控制
         */

        if ((scale < initScale * SCALE_MAX && scaleFactor > 1.0f)
                || (scale > initScale * SCALE_MID && scaleFactor < 1.0f)) {
            /**
             * 最大值最小值判断
             */
            if (scaleFactor * scale < initScale * SCALE_MID) {
                scaleFactor = initScale * SCALE_MID / scale;
            }
            if (scaleFactor * scale > initScale * SCALE_MAX) {
                scaleFactor = initScale * SCALE_MAX / scale;
            }
            /**
             * 设置缩放比例
             */
            mScaleMatrix.postScale(scaleFactor, scaleFactor,
                    detector.getFocusX(), detector.getFocusY());
            checkBorderAndCenterWhenScale();
            setImageMatrix(mScaleMatrix);
        }
        return true;

    }

    /**
     * 在缩放时，进行图片显示范围的控制
     */
    private void checkBorderAndCenterWhenScale() {

        RectF rect = getMatrixRectF();
        float deltaX = 0;
        float deltaY = 0;

        int width = getWidth();
        int height = getHeight();

        // 如果宽或高大于屏幕，则控制范围
        if (rect.width() >= width) {
            if (rect.left > 0) {
                deltaX = -rect.left;
            }
            if (rect.right < width) {
                deltaX = width - rect.right;
            }
        }
        if (rect.height() >= height) {
            if (rect.top > 0) {
                deltaY = -rect.top;
            }
            if (rect.bottom < height) {
                deltaY = height - rect.bottom;
            }
        }
        // 如果宽或高小于屏幕，则让其居中
        if (rect.width() < width) {
            deltaX = width * 0.5f - rect.right + 0.5f * rect.width();
        }
        if (rect.height() < height) {
            deltaY = height * 0.5f - rect.bottom + 0.5f * rect.height();
        }
        Trace.e(TAG, "deltaX = " + deltaX + " , deltaY = " + deltaY);

        mScaleMatrix.postTranslate(deltaX, deltaY);

    }

    /**
     * 根据当前图片的Matrix获得图片的范围
     *
     * @return
     */
    private RectF getMatrixRectF() {
        Matrix matrix = mScaleMatrix;
        RectF rect = new RectF();
        Drawable d = getDrawable();
        if (null != d) {
            rect.set(0, 0, d.getIntrinsicWidth(), d.getIntrinsicHeight());
            matrix.mapRect(rect);
        }
        return rect;
    }

    @Override
    public boolean onScaleBegin(ScaleGestureDetector detector) {
        return true;
    }

    @Override
    public void onScaleEnd(ScaleGestureDetector detector) {
        float scale = getScale();
        if (scale < initScale && !mIsScaling) {
            //当小于屏幕时，执行回弹动画
            valueAnimator.start();
        }
    }

    //回弹动画
    private ValueAnimator valueAnimator = new ValueAnimator();

    private void initAnimator() {
        //回弹动画
        valueAnimator.setFloatValues(0f, 1f);
        valueAnimator.setDuration(300);
        valueAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
            @Override
            public void onAnimationUpdate(ValueAnimator animation) {
                float scale = getScale();
                if (scale < initScale) {
                    if (scale * xx < initScale) {
                        mScaleMatrix.postScale(xx, xx, getWidth() / 2,
                                getHeight() / 2);
                    } else {
                        mScaleMatrix.postScale(initScale / scale, initScale / scale, getWidth() / 2,
                                getHeight() / 2);
                    }
                    setImageMatrix(mScaleMatrix);
                }
            }
        });
        valueAnimator.addListener(new Animator.AnimatorListener() {
            @Override
            public void onAnimationStart(Animator animation) {
                mIsScaling = true;
            }

            @Override
            public void onAnimationEnd(Animator animation) {
                mIsScaling = false;
            }

            @Override
            public void onAnimationCancel(Animator animation) {

            }

            @Override
            public void onAnimationRepeat(Animator animation) {

            }
        });
    }

    @Override
    public boolean onTouch(View v, MotionEvent event) {

//        if (mGestureDetector.onTouchEvent(event))
//            return true;
        mScaleGestureDetector.onTouchEvent(event);

        float x = 0, y = 0;
        // 拿到触摸点的个数
        final int pointerCount = event.getPointerCount();
        // 得到多个触摸点的x与y均值
        for (int i = 0; i < pointerCount; i++) {
            x += event.getX(i);
            y += event.getY(i);
        }
        x = x / pointerCount;
        y = y / pointerCount;

        /**
         * 每当触摸点发生变化时，重置mLasX , mLastY
         */
        if (pointerCount != mLastPointerCount) {
            mCanDrag = false;
            mLastX = x;
            mLastY = y;
        }

        mLastPointerCount = pointerCount;
        RectF rectF = getMatrixRectF();
        switch (event.getAction()) {
            case MotionEvent.ACTION_DOWN:
                if (rectF.width() > getWidth() || rectF.height() > getHeight()) {
                    getParent().requestDisallowInterceptTouchEvent(true);
                }
                break;
            case MotionEvent.ACTION_MOVE:
                if (rectF.width() > getWidth() || rectF.height() > getHeight()) {
                    getParent().requestDisallowInterceptTouchEvent(true);
                }
                Trace.e(TAG, "ACTION_MOVE");
                float dx = x - mLastX;
                float dy = y - mLastY;

                if (!mCanDrag) {
                    mCanDrag = isCanDrag(dx, dy);
                }
                if (mCanDrag) {
                    if (getDrawable() != null) {
                        if (getMatrixRectF().left == 0 && dx > 0) {
                            getParent().requestDisallowInterceptTouchEvent(false);
                        }

                        if (getMatrixRectF().right == getWidth() && dx < 0) {
                            getParent().requestDisallowInterceptTouchEvent(false);
                        }
                        mIsCheckLeftAndRight = mIsCheckTopAndBottom = true;
                        // 如果宽度小于屏幕宽度，则禁止左右移动
                        if (rectF.width() < getWidth()) {
                            dx = 0;
                            mIsCheckLeftAndRight = false;
                        }
                        // 如果高度小于屏幕高度，则禁止上下移动
                        if (rectF.height() < getHeight()) {
                            dy = 0;
                            mIsCheckTopAndBottom = false;
                        }


                        mScaleMatrix.postTranslate(dx, dy);
                        checkMatrixBounds();
                        setImageMatrix(mScaleMatrix);
                    }
                }
                mLastX = x;
                mLastY = y;
                break;
            case MotionEvent.ACTION_UP:
            case MotionEvent.ACTION_CANCEL:
                Trace.e(TAG, "ACTION_UP");
                mLastPointerCount = 0;
                break;
        }

        return true;
    }

    /**
     * 获得当前的缩放比例
     *
     * @return
     */
    public final float getScale() {
        mScaleMatrix.getValues(mMatrixValues);
        return mMatrixValues[Matrix.MSCALE_X];
    }

    @Override
    protected void onAttachedToWindow() {
        super.onAttachedToWindow();
        getViewTreeObserver().addOnGlobalLayoutListener(this);
    }

    @SuppressWarnings("deprecation")
    @Override
    protected void onDetachedFromWindow() {
        super.onDetachedFromWindow();
        getViewTreeObserver().removeGlobalOnLayoutListener(this);
    }

    @Override
    public void onGlobalLayout() {
        if (mOnce) {
            Drawable d = getDrawable();
            if (d == null)
                return;
            Trace.e(TAG, d.getIntrinsicWidth() + " , " + d.getIntrinsicHeight());
            int width = getWidth();
            int height = getHeight();
            // 拿到图片的宽和高
            int dw = d.getIntrinsicWidth();
            int dh = d.getIntrinsicHeight();
            float scale = 1.0f;
            // 如果图片的宽或者高大于屏幕，则缩放至屏幕的宽或者高
            if (dw > width && dh <= height) {
                scale = width * 1.0f / dw;
            }
            if (dh > height && dw <= width) {
                scale = height * 1.0f / dh;
            }
            // 如果宽和高都大于屏幕，则让其按按比例适应屏幕大小
            if (dw > width && dh > height) {
                scale = Math.min(width * 1.0f / dw, height * 1.0f / dh);
            }

            if (dw < width && dh < height) {
                scale = Math.min(width * 1.0f / dw, height * 1.0f / dh);
            }

            initScale = scale;

            Trace.e(TAG, "initScale = " + initScale);
            mScaleMatrix.postTranslate((width - dw) / 2, (height - dh) / 2);
            mScaleMatrix.postScale(scale, scale, getWidth() / 2,
                    getHeight() / 2);
            // 图片移动至屏幕中心
            setImageMatrix(mScaleMatrix);
            mOnce = false;
        }

    }

    /**
     * 移动时，进行边界判断，主要判断宽或高大于屏幕的
     */
    private void checkMatrixBounds() {
        RectF rect = getMatrixRectF();

        float deltaX = 0, deltaY = 0;
        final float viewWidth = getWidth();
        final float viewHeight = getHeight();
        // 判断移动或缩放后，图片显示是否超出屏幕边界
        if (rect.top > 0 && mIsCheckTopAndBottom) {
            deltaY = -rect.top;
        }
        if (rect.bottom < viewHeight && mIsCheckTopAndBottom) {
            deltaY = viewHeight - rect.bottom;
        }
        if (rect.left > 0 && mIsCheckLeftAndRight) {
            deltaX = -rect.left;
        }
        if (rect.right < viewWidth && mIsCheckLeftAndRight) {
            deltaX = viewWidth - rect.right;
        }
        mScaleMatrix.postTranslate(deltaX, deltaY);
    }

    /**
     * 是否是推动行为
     *
     * @param dx
     * @param dy
     * @return
     */
    private boolean isCanDrag(float dx, float dy) {
        return Math.sqrt((dx * dx) + (dy * dy)) >= mTouchSlop;
    }

}
